Europium(III) tris-dibenzoylmethanate as an efficient chemosensor for detection of ammonia

The effect of ammonia vapor on luminescence of Eu(III) tris-dibenzoylmethanate immobilized in various matrices has been investigated. It has been revealed that interaction of Eu(III) tris-dibenzoylmethanate with analyte vapor results in increase of the intensity of Eu(III) luminescence. The mechanism of the effect of ammonia vapors on intensification of the Eu(III) luminescence has been suggested using the data of IR spectroscopy, X-ray diffraction analysis and quantum chemistry calculations. The mechanism of luminescence sensitization consists in bonding of an analyte molecule with a water molecule into the coordination sphere of Eu(III). As a result, the bond of a water molecule with the luminescence centre weakens and the blockage of the quenching of luminescence on OH-vibrations takes place.